Definition and mechanism
On The Bob Zadek Show, herd immunity was described by Jeff Singer as the point at which enough people have immunity to a virus that it cannot find enough hosts and vectors to spread through the population to any significant degree, so that it is no longer a menace to the public. Singer said there would always be a case here or there, but not enough to be a huge social problem, and that a population reaches that point either through vaccinating the entire population or through enough people getting the disease and developing immunity, usually a combination of the two. He noted that in some cases no vaccine is ever developed, citing twenty years of effort on HIV and the absence of one for hepatitis C, and that only one virus affecting humans has ever been eradicated, the smallpox virus. Here comes “the spike…” (2020)
In a later episode, Dr. Jeffrey Singer returned to the concept while discussing the COVID-19 vaccines, saying that reaching something close to herd immunity was the ticket out of the pandemic and that it does not require everyone to be vaccinated, because another route to immunity is infection followed by natural immunity. He said he did not recommend that approach, preferring vaccination to risking illness and death. Vaccines & the Totalitarian Principle (2021)
Herd immunity and the lockdown debate
Singer’s account of herd immunity came inside a broader argument about how executives made lockdown decisions. He said that in his opinion executives all too frequently deferred all decision-making to public health officials, asking what needed to be done to eradicate the virus and then implementing whatever the officials said. He argued that public health officials look through one narrow lens—getting rid of the virus—and do not pretend to be experts on economics or sociology, so they do not consider the economic, social, or long-term unintended consequences of the interventions they recommend. It was, in his view, the executive’s job to consult economists and political advisers as well, to weigh first-, second-, and third-best solutions, and to balance the trade-offs. Here comes “the spike…” (2020)
Singer illustrated the point with an exchange he recalled between Senator Rand Paul and Dr. Fauci, in which Fauci said he was not an economist and did not pretend to be one, but was a public health expert giving public health insights. Singer compared the dynamic to hiring a pest control operator to eradicate roaches and returning to find the house burned down. He also said that one advantage of the federal system is that one size does not fit all, and that situations on the ground in the New York metropolitan area were not the same as in South Dakota or California, with population density, demographics, and the age of the population all playing into the decision. Here comes “the spike…” (2020)
In the earlier episode, Jacob Sullum made a related cost-benefit argument. He said that if the true mortality rate turned out to be in the vicinity of the seasonal flu’s—somewhat larger but not a lot larger—it would be an enormous mistake to have plunged the country into a severe recession over the virus, and that the answer to how much more deadly COVID-19 is has a dramatic impact on which policies make sense. He noted that when governments impose regulations aimed at protecting public safety and health, they routinely take into account not just how many lives will be saved but how much it will cost, assigning a dollar value usually around $8 or $9 million to each life saved or death prevented. How to Stay Sane as a Libertarian on Lockdown (2020)
Sullum also framed the shorter-term question as whether hospitals had been overwhelmed, because that would mean not only that not everyone with COVID-19 could be treated but that people with other serious conditions might not get the treatment they needed, leading to additional deaths. He described the path from total lockdown back to a functioning economy as requiring testing at a level the country had not achieved, including antibody tests to identify people who had been infected and recovered and presumably had immunity—though he called that another completely unknown thing. He raised the alternative of more narrowly tailored approaches that protect the elderly and people with serious pre-existing conditions without shutting down everything, and said he did not see enough discussion of that by politicians. How to Stay Sane as a Libertarian on Lockdown (2020)
Vaccination, behavior, and the immunized
In April 2021, Bob Zadek asked Dr. Jeffrey Singer how he behaved now that he was vaccinated, describing mixed messaging from the CDC and quoting Rochelle Walensky saying in the same sentence that once vaccinated there is not much to worry about and that we are doomed. Singer said the mixed messaging was really harmful because the ticket out of the mess was to reach something close to herd immunity. Vaccines & the Totalitarian Principle (2021)
Singer said the mRNA vaccines were a brand new technology that does not use a live, dead, or modified virus but messenger RNA, and that they were incredibly effective. He said that while medical science is never 100 percent, a vaccinated person is pretty much guaranteed not to get severely ill enough to be hospitalized and not to die, with upwards of 95 percent or more protection against even getting the virus depending on the vaccine. He said a very tiny percentage of people may become asymptomatically infected and unknowingly carry the virus, but that data first from Israel and then reported by the CDC showed that even among those who become asymptomatically infected, viral titers and viral load seem greatly reduced by vaccination, and that asymptomatic vaccinated people who become infected have it even lower. Vaccines & the Totalitarian Principle (2021)
From that, Singer drew behavioral conclusions. He said he could hang out with other immunized people without concern, take his mask off, hug, kiss, and shake hands, because he was highly unlikely to spread the virus to someone who was highly unlikely to contract it. Among unvaccinated people, he said he did not have to worry about them giving him the virus, and the chances of him spreading it to them were extremely unlikely; he still recommended caution around extremely vulnerable unimmunized people, such as a chronically ill or frail relative, because one would feel awful to be the rare case that spread the virus to them. He said it made no sense to wear a mask outside even before the vaccine, that the virus spreads usually by aerosol at relatively close contact, and that passing someone on a sidewalk for one second is not a transmission event. He said that as a libertarian he respects property rights, so when a store says masks are required he obeys, and that practically, in a supermarket full of strangers whose vaccination status is unknown, it is easier for everybody to wear a mask so nobody is frightened. Vaccines & the Totalitarian Principle (2021)
Herd immunity and harm to others
In September 2021, Bob Levy framed the vaccine mandate debate through libertarian first principles. He said the core libertarian principle is the right to live your life as you choose as long as you do not inflict harm on others, and that personal autonomy is at issue with the vaccine particularly because it involves the injection of a medical substance into the body. He said it has always been a core libertarian principle that your right to punch ends where my nose begins, and that the controversy boils down to whether a person can refuse injection notwithstanding that the refusal might visit risks on other people—a close call, unlike most libertarian questions, which fall comfortably on one side of the line or the other. A Libertarian Legal Perspective on Vaccine Mandates (2021)
Levy identified three classes of persons he said were harmed. The first is people who cannot be vaccinated for medical reasons and could contract COVID from an unvaccinated person. The second is people who cannot obtain medical treatment for other ailments because unvaccinated COVID patients have strained hospital capacity, equipment, and staff; he said almost all hospitalizations for COVID are unvaccinated persons, and described spending two full days in an emergency area for something unrelated to COVID because no general-admission beds were available. The third is people who have been or may be afflicted by the Delta variant, which he said probably would not have mutated if a larger percentage of the population had been vaccinated, especially if herd immunity had been reached. He noted that the class of unvaccinated persons may be relatively small but currently includes all children under the age of 12, quite a few of whom were experiencing more serious problems because of the Delta variant. On that basis he said it is plausible to argue that a pristine libertarian perspective on personal autonomy comes into question when one is causing harm to lots of other folks. A Libertarian Legal Perspective on Vaccine Mandates (2021)
Across episodes: the same question, argued twice
Herd immunity appears in two distinct treatments. In June 2020, Jeff Singer described it as the epidemiological endpoint that executives should have been weighing against the costs of lockdown, and criticized decision-makers for delegating to public health officials who looked through one narrow lens. In April 2021, Dr. Jeffrey Singer described it as the ticket out of the pandemic and used it to justify relaxed behavior among the immunized, while still recommending caution around the vulnerable. In September 2021, Bob Levy used the failure to reach herd immunity as part of an argument that the unvaccinated cause harm to identifiable third parties, shifting the concept from a policy benchmark to a ground for coercion. What changed between the earlier and later treatments is the direction of the argument: the 2020 discussion treated herd immunity as a reason to reopen and to weigh trade-offs, while the 2021 discussions treated it as a reason to vaccinate and, in Levy’s case, as a reason mandates might be defensible. Here comes “the spike…” (2020) Vaccines & the Totalitarian Principle (2021) A Libertarian Legal Perspective on Vaccine Mandates (2021)
What the sources do not cover
The excerpts do not state the specific threshold percentage of the population required for herd immunity, nor do they give a numerical estimate of the COVID-19 mortality rate. They do not describe the legal reasoning or holding of any vaccine mandate case, nor identify the statute or amendment on which such challenges turned. The excerpts also do not state the founding date or institutional history of any public health agency, and several sections end mid-sentence or at a speaker label with no following text.